Selective Attention Processes Research Articles

Mapping cognitive brain functions at scale

A fundamental set of cognitive abilities enable humans to efficiently process goal-relevant information, suppress irrelevant distractions, maintain information in working memory, and act flexibly in different behavioral contexts. Yet, studies of human cognition and their underlying neural mechanisms usually evaluate these cognitive constructs in silos, instead of comprehensively in-tandem within the same individual. Here, we developed a scalable, mobile platform, “BrainE” (short for Brain Engagement), to rapidly assay several essential aspects of cognition simultaneous with wireless electroencephalography (EEG) recordings. Using BrainE, we rapidly assessed five aspects of cognition including (1) selective attention, (2) response inhibition, (3) working memory, (4) flanker interference and (5) emotion interference processing, in 102 healthy young adults. We evaluated stimulus encoding in all tasks using the EEG neural recordings, and isolated the cortical sources of the spectrotemporal EEG dynamics. Additionally, we used BrainE in a two-visit study in 24 young adults to investigate the reliability of the neuro-cognitive data as well as its plasticity to transcranial magnetic stimulation (TMS). We found that stimulus encoding on multiple cognitive tasks could be rapidly assessed, identifying common as well as distinct task processes in both sensory and cognitive control brain regions. Event related synchronization (ERS) in the theta (3-7 Hz) and alpha (8-12 Hz) frequencies as well as event related desynchronization (ERD) in the beta frequencies (13-30 Hz) were distinctly observed in each task. The observed ERS/ERD effects were overall anticorrelated. The two-visit study confirmed high test-retest reliability for both cognitive and neural data, and neural responses showed specific TMS protocol driven modulation. We also show that the global cognitive neural responses are sensitive to mental health symptom self-reports. This first study with the BrainE platform showcases its utility in studying neuro-cognitive dynamics in a rapid and scalable fashion.

Accelerated repetitive transcranial magnetic stimulation in the treatment of post-concussion symptoms due to mild traumatic brain injury: a pilot study

ABSTRACT Objective: To investigate the feasibility, tolerability, and efficacy of twice-daily, low frequency (LF) repetitive transcranial magnetic stimulation (rTMS) over the right dorsolateral prefrontal cortex (DLPFC) in the reduction of chronic post-concussion symptoms (PCS) in patients who have suffered a mild traumatic brain injury (mTBI). Methods: 15 patients with mTBI received 30 sessions of twice-daily LF rTMS (1 Hz) over the right DLPFC. Post-concussion symptoms, pain, disability, fatigue, apathy, agitation, and mood were assessed by a psychiatrist pre- and post-treatment. Cognitive testing was also performed pre-, mid-, and post-rTMS. Results: All participants completed treatment with no serious adverse events. Significant improvements were observed in overall post-concussion symptoms, disability and pain ratings, as well as depression and anxiety symptoms. There was no significant change in overall executive functioning, fatigue severity, apathy, or agitation. Cognitive testing revealed improvements in verbal fluency, working memory, selective attention, and cognitive processing speed. Conclusions: This small-sample pilot study suggests that twice-daily, LF rTMS over the right DLPFC can be safely and tolerably applied and has the potential to improve post-concussion symptoms as well as elements of mood and cognition in patients with mTBI. Larger, sham-controlled studies will be important to confirm these observations.

Acute stress reduces the emotional attentional blink: Evidence from human electrophysiology.

The present study is the first to examine the time-dependent mechanism of acute stress on emotional attentional blink (EAB) with event-related potential (ERP) measures. We explored the stage characteristics of stress affecting EAB, whether it affects the early selective attention process (marked by early posterior negativity) or the late working memory consolidation (marked by late positive potential). Sixty-one healthy participants were exposed to either a Trier Social Stress Test (TSST) or a control condition, and salivary cortisol was measured to reflect the stress effect. ERPs were recorded during an attentional blink (AB) paradigm in which target one (T1) were negative or neutral images. Results showed stress generally reduced AB effects. Specifically, stress promoted the early selective attention process of target two (T2) following a neutral T1 but did not affect T2 consolidation into working memory. Correlational analyses further confirmed the positive effect of cortisol and negative emotional state on AB performance. Moreover, the ERP results of acute stress on AB conformed to the trade-off effect between T1 and T2; that is, stress reduced T1 late working memory consolidation and improved T2 early selective attention process. These findings further demonstrated that stress did not change the central resource limitation of AB. In general, stress generates a dissociable effect on AB early- and late-stage processing; namely, acute stress reduce the AB effect mainly from the improvement of participants' overall ability to select the targets in the early stage.

Altered fronto-occipital connectivity during visual selective attention in regular cannabis users

Cognitive processing impairments have been associated with acute cannabis use, but there is mixed evidence regarding the cognitive effects of chronic cannabis use. Several neuroimaging studies have noted selective-attention processing differences in those who chronically use cannabis, but the neural dynamics governing the altered processing is unclear. Twenty-four adults reporting at least weekly cannabis use in the past 6months on the Cannabis Use Disorder Identification Test - Revised were compared to 24 demographically matched controls who reported no prior cannabis use. All participants completed a visual selective attention processing task while undergoing magnetoencephalography. Time-frequency windows of interest were identified using a data-driven method, and spectrally specific neural activity was imaged using a beamforming approach. All participants performed within normal range on the cognitive task. Regular cannabis users displayed an aberrant cognitive interference effect in the theta (4-8Hz) frequency range shortly after stimulus onset (i.e., 0-250ms) in the right occipital cortex. Cannabis users also exhibited altered functional connectivity between the right prefrontal cortex and right occipital cortices in comparison to controls. Individuals with a history of regular cannabis use exhibited abnormal theta interference activity in the occipital cortices, as well as altered prefrontal-occipital functional connectivity in the theta range during a visual selective attention task. Such differences may reflect compensatory processing, as these participants performed within normal range on the task. Understanding the neural dynamics in chronic, regular cannabis users may provide insight on how long-term and/or frequent use may affect neural networks underlying cognitive processes.

How can we learn what attention is? Response gating via multiple direct routes kept in check by inhibitory control processes

AbstractTo explore the time course of space- and object-based attentional selection processes I analysed the shapes of the response time (RT) and accuracy distributions of left/right arrow identification responses in the two-rectangle paradigm. After cueing one of the four ends of two horizontally or vertically oriented rectangles the arrow typically appears at the cued location (valid), or sometimes at an uncued location in the same (invalid-same) or other rectangle (invalid-different). The data point to a multiple-route model in which (a) an informative cue generates response channel activation before arrow signals emerge, (b) the task-irrelevant arrow location is represented in multiple egocentric and allocentric reference frames around 150 ms after target onset, with the former including a reference frame centered on the currently attended location, (c) the task-irrelevant spatial codes activate premature response tendencies that are actively inhibited to allow gating of arrow direction signals, (d) after an invalid cue the onset of the arrow triggers an “attention shift” – acting between 150 and 240 ms after target onset – that strongly interferes with task performance in certain conditions (invalid-same cueing with horizontal rectangles, and invalid-different cueing with vertical rectangles), and (e) participants differ in which task-irrelevant codes they preferentially inhibit. These results pave the way for future confirmatory studies to temporally characterize and disentangle the contributions of different types of response channel activation processes, from those of reactive cognitive control processes including active and selective response suppression.

Adaptability to acute stress among women survivors of intimate partner violence: protocol for a mixed-methods cross-sectional study in a laboratory setting (BRAW study)

IntroductionIntimate partner violence (IPV) is the most common and alarming form of violence against women, affecting around 30% of all women around the world. Using an integrative methodology, we approach...

Using a multidimensional model of attention to predict low-income preschoolers' early academic skills across time.

The current study examines the organization of attention skills across the preschool year before kindergarten, and tests how distinct attention subcomponents predict early academic skills in a sample of low-income children (n=99). Children completed well-validated attention tasks in fall at 4.5 years old and spring at 5 years old, capturing the abilities to selectively focus, sustain attention, and employ executive control. Exploratory factor analyses at both time points support a 2-factor model differentiating selective and sustained attention from attention processing speed and executive attention, suggesting that attention in low-income preschoolers may have a simpler organization than the 3-factor structure found in adulthood. Multiple regression models find children's ability to selectively focus and sustain attention serves as a robust concurrent and longitudinal predictor of academic skills. These results highlight the role of selective and sustained attention processes in supporting school readiness for economically vulnerable children.

Analysis of selective attention processing on experienced simultaneous interpreters using EEG phase synchronization.

This study analyzed the selective attention processing related to cognitive load on simultaneous interpretation (SI). We tested simultaneous interpreter's brain function using EEG signals and calculated inter-trial coherence (ITC) extracted by the 40-Hz auditory steady-state response (ASSR). In this experiment, we set two conditions as Japanese-English translation and Japanese shadowing cognition. We also compared two subject groups: S rank with more than 15 years of SI experience (n=7) and C rank with less than one year experience (n=15). As a result, the ITCs for S rank in interpreting conditions were more significantly increased than C rank in the shadowing conditions (ITC: p<0.001). Our results demonstrate that 40-Hz ASSR might be a good indicator of selective attention and cognitive load during SI in ecologically valid environmental conditions. It can also be used to detect attention and cognitive control dysfunction in ADHD or schizophrenia.

Examining the effects of musical type and intensity in performing the flanker task: A test of attentional control theory applied to non-emotional distractions

Music alters the interplay between components of cognition and performance; however, there are inconclusive findings on how. One explanation may be Attentional Control Theory, which states that anxiety places demands on cognitive resources producing adverse effects on cognitive performance. Similarly, characteristics of music alter cognitive faculties resulting in poor performance. Therefore, the current study aimed to investigate effects on cognition specific to influences of music through the lens of Attentional Control Theory. In an attempt to explain how music impacts cognitive performance, we asked 141 college students (63.1% female) to complete the flanker task while listening to either lyrical or non-lyrical music at differing sound intensities. Results revealed a significant main effect of music type on flanker performance; however, no significant differences emerged with sound intensity. Findings suggest music with lyrics, rather than intensity, impairs cognition in adults, thereby elucidating the importance of avoiding music with lyrics during active tasks. Moreover, musical lyrics worsen performance by either interfering with selective attention processing of goal-relevant information or altering working memory capacity resulting in decreases in processing efficiency and performance effectiveness. Therefore, findings support the use of attentional control theory as a means of explaining differences in cognitive performance due to characteristics of music.

The Neuropsychological Profile of Attention Deficits of Patients with Obstructive Sleep Apnea: An Update on the Daytime Attentional Impairment.

Introduction: Patients with obstructive sleep apnea (OSA) suffer from several neurocognitive disturbances. One of the neuropsychological processes most investigated in OSA patients is attention, but the results have been controversial. Here, we update the attention profile of OSA patients with the final aim to improve attention assessment, with a possible impact on clinical and medical-legal practices, in terms of which attention subdomains and parameters need consideration and which one is a high-risk OSA phenotype for attention dysfunctions. Method: For this purpose, we assessed 32 previously untreated OSA patients (26 men and 6 women) under 65 years of age (mean age 53.2 ± 7.3; mean education level 10.4 ± 3.4 years) suffering from moderate to severe sleep apnea and hypopnea (mean apnea-hypopnea index (AHI) 45.3 ± 22.9, range 16.1–69.6). A control group of 34 healthy participants matched with OSA patients for age, education level, and general cognitive functioning were also enrolled. The OSA patients and healthy participants were tested through an extensive computerized battery (Test of Attentional Performance, TAP) that evaluated intensive (i.e., alertness and vigilance) and selective (i.e., divided and selective) dimensions of attention and returned different outcome parameters (i.e., reaction time, stability of performance, and various types of errors). Data analysis: The data were analyzed by ANCOVA which compared the speed and accuracy performance of the OSA and control participants (cognitive reserve was treated as a covariate). The possible mechanisms underlying attention deficits in OSA patients were examined through correlation analysis among AHI, oxygenation parameters, sleepiness scores, and TAP outcomes and by comparing the following three phenotypes of patients: severe OSA and severe nocturnal desaturators (AHI++D+), severe OSA nondesaturators (AHI++D−), and moderate OSA nondesaturators (AHI+D−). Results: The results suggest that the OSA patients manifest deficits in both intensive and selective attention processes and that reaction time (RT) alone is ineffective for detecting and characterizing their problems, for which error analysis and stability of performance also have to be considered. Patients with severe OSA and severe hypoxemia underperformed on alertness and vigilance attention subtests. Conclusions: The data suggest the importance of evaluating attention deficits among OSA patients through several parameters (including performance instability). Moreover, the data suggest a multifaceted mechanism underlying attention dysfunction in OSA patients.

Tracking the Effects of Top-Down Attention on Word Discrimination Using Frequency-tagged Neuromagnetic Responses.

Discrimination of words from nonspeech sounds is essential in communication. Still, how selective attention can influence this early step of speech processing remains elusive. To answer that question, brain activity was recorded with magnetoencephalography in 12 healthy adults while they listened to two sequences of auditory stimuli presented at 2.17 Hz, consisting of successions of one randomized word (tagging frequency = 0.54 Hz) and three acoustically matched nonverbal stimuli. Participants were instructed to focus their attention on the occurrence of a predefined word in the verbal attention condition and on a nonverbal stimulus in the nonverbal attention condition. Steady-state neuromagnetic responses were identified with spectral analysis at sensor and source levels. Significant sensor responses peaked at 0.54 and 2.17 Hz in both conditions. Sources at 0.54 Hz were reconstructed in supratemporal auditory cortex, left superior temporal gyrus (STG), left middle temporal gyrus, and left inferior frontal gyrus. Sources at 2.17 Hz were reconstructed in supratemporal auditory cortex and STG. Crucially, source strength in the left STG at 0.54 Hz was significantly higher in verbal attention than in nonverbal attention condition. This study demonstrates speech-sensitive responses at primary auditory and speech-related neocortical areas. Critically, it highlights that, during word discrimination, top-down attention modulates activity within the left STG. This area therefore appears to play a crucial role in selective verbal attentional processes for this early step of speech processing.

Poor early cortical differentiation of speech predicts perceptual difficulties of severely hearing-impaired listeners in multi-talker environments

Hearing impairment disrupts processes of selective attention that help listeners attend to one sound source over competing sounds in the environment. Hearing prostheses (hearing aids and cochlear implants, CIs), do not fully remedy these issues. In normal hearing, mechanisms of selective attention arise through the facilitation and suppression of neural activity that represents sound sources. However, it is unclear how hearing impairment affects these neural processes, which is key to understanding why listening difficulty remains. Here, severely-impaired listeners treated with a CI, and age-matched normal-hearing controls, attended to one of two identical but spatially separated talkers while multichannel EEG was recorded. Whereas neural representations of attended and ignored speech were differentiated at early (~ 150 ms) cortical processing stages in controls, differentiation of talker representations only occurred later (~250 ms) in CI users. CI users, but not controls, also showed evidence for spatial suppression of the ignored talker through lateralized alpha (7–14 Hz) oscillations. However, CI users’ perceptual performance was only predicted by early-stage talker differentiation. We conclude that multi-talker listening difficulty remains for impaired listeners due to deficits in early-stage separation of cortical speech representations, despite neural evidence that they use spatial information to guide selective attention.

Applying deep learning to single-trial EEG data provides evidence for complementary theories on action control

Efficient action control is indispensable for goal-directed behaviour. Different theories have stressed the importance of either attention or response selection sub-processes for action control. Yet, it is unclear to what extent these processes can be identified in the dynamics of neurophysiological (EEG) processes at the single-trial level and be used to predict the presence of conflicts in a given moment. Applying deep learning, which was blind to cognitive theory, on single-trial EEG data allowed to predict the presence of conflict in ~95% of subjects ~33% above chance level. Neurophysiological features related to attentional and motor response selection processes in the occipital cortex and the superior frontal gyrus contributed most to prediction accuracy. Importantly, deep learning was able to identify predictive neurophysiological processes in single-trial neural dynamics. Hence, mathematical (artificial intelligence) approaches may be used to foster the validation and development of links between cognitive theory and neurophysiology of human behavior.

Retrospective Selection in Visual and Tactile Working Memory Is Mediated by Shared Control Mechanisms.

Selective attention regulates the activation of working memory (WM) representations. Retro-cues, presented after memory sample stimuli have been stored, modulate these activation states by triggering shifts of attention to task-relevant samples. Here, we investigated whether the control of such attention shifts is modality-specific or shared across sensory modalities. Participants memorized bilateral tactile and visual sample stimuli before an auditory retro-cue indicated which visual and tactile stimuli had to be retained. Critically, these cued samples were located on the same side or opposite sides, thus requiring spatially congruent or incongruent attention shifts in tactile and visual WM. To track the attentional selection of retro-cued samples, tactile and visual contralateral delay activities (tCDA and CDA components) were measured. Clear evidence for spatial synergy effects from attention shifts in visual WM on concurrent shifts in tactile WM were observed: Tactile WM performance was impaired, and tCDA components triggered by retro-cues were strongly attenuated on opposite-sides relative to same-side trials. These spatial congruency effects were eliminated when cued attention shifts in tactile WM occurred in the absence of simultaneous shifts within visual WM. Results show that, in contrast to other modality-specific aspects of WM control, concurrent attentional selection processes within tactile and visual WM are mediated by shared supramodal control processes.

Auditory detection learning is accompanied by plasticity in the auditory evoked potential

Auditory detection can improve with practice. These improvements are often assumed to arise from selective attention processes, but longer-term plasticity as a result of training may also play a role. Here, listeners were trained to detect either an 861-Hz or 1058-Hz tone (counterbalanced across participants) presented in noise at SNRs varying from -10 to -24 dB. On the following day, they were tasked with detecting 861-Hz and 1058-Hz tones at an SNR of -21 dB. In between blocks of this active task, EEG was recorded during passive presentation of trained and untrained frequency tones in quiet. Detection accuracy and confidence ratings were higher for trials at listeners’ trained, than untrained-frequency (i.e., learning occurred). During passive exposure to sounds, the P2 component of the auditory evoked potential (∼150 – 200 ms post tone onset) was larger in amplitude for the trained compared to the untrained frequency. An analysis of global field power similarly yielded a stronger response for trained tones in the P2 time window. These effects were obtained during passive exposure, suggesting that training induced improvements in detection are not solely related to changes in selective attention. Rather, there may be an important role for changes in the long-term neural representations of sounds.

Studying the dynamics of visual search behavior using RT hazard and micro-level speed-accuracy tradeoff functions: A role for recurrent object recognition and cognitive control processes.

Thanks to the work of Anne Treisman and many others, the visual search paradigm has become one of the most popular paradigms in the study of visual attention. However, statistics like mean correct response time (RT) and percent error do not usually suffice to decide between the different search models that have been developed. Recently, to move beyond mean performance measures in visual search, RT histograms have been plotted, theoretical waiting time distributions have been fitted, and whole RT and error distributions have been simulated. Here we promote and illustrate the general application of discrete-time hazard analysis to response times, and of micro-level speed-accuracy tradeoff analysis to timed response accuracies. An exploratory analysis of published benchmark search data from feature, conjunction, and spatial configuration search tasks reveals new features of visual search behavior, such as a relatively flat hazard function in the right tail of the RT distributions for all tasks, a clear effect of set size on the shape of the RT distribution for the feature search task, and individual differences in the presence of a systematic pattern of early errors. Our findings suggest that the temporal dynamics of visual search behavior results from a decision process that is temporally modulated by concurrently active recurrent object recognition, learning, and cognitive control processes, next to attentional selection processes.

Early Attentional Modulation by Working Memory Training in Young Adult ADHD Patients during a Risky Decision-Making Task.

Background: Working memory (WM) deficits and impaired decision making are among the characteristic symptoms of patients affected by attention deficit/hyperactivity disorder (ADHD). The inattention associated with the disorder is likely to be due to functional deficits of the neural networks inhibiting irrelevant sensory input. In the presence of unnecessary information, a good decisional process is impaired and ADHD patients tend to take risky decisions. This study is aimed to test the hypothesis that the level of difficulty of a WM training (WMT) is affecting the top-down modulation of the attentional processes in a probabilistic gambling task. Methods: Event-related potentials (ERP) triggered by the choice of the amount wagered in the gambling task were recorded, before and after WMT with a the dual n-back task, in young ADHD adults and matched controls. For each group of participants, randomly assigned individuals were requested to perform WMT with a fixed baseline level of difficulty. The remaining participants were trained with a performance-dependent adaptive n-level of difficulty. Results: We compared the ERP recordings before and after 20 days of WMT in each subgroup. The analysis was focused on the time windows with at least three recording sites showing differences before and after training, after Bonferroni correction (). In ADHD, the P1 wave component was selectively affected at frontal sites and its shape was recovered close to controls’ only after adaptive training. In controls, the strongest contrast was observed at parietal level with a left hemispheric dominance at latencies near 900 ms, more after baseline than after adaptive training. Conclusion: Partial restoration of early selective attentional processes in ADHD patients might occur after WMT with a high cognitive load. Modified frontal sites’ activities might constitute a neural marker of this effect in a gambling task. In controls, conversely, an increase in late parietal negativity might rather be a marker of an increase in transfer effects to fluid intelligence.

Acute psychological stress promotes general alertness and attentional control processes: An ERP study.

The current study investigated the influence of acute psychological stress on selective attention processes. After an acute stressor or a control condition, 20 participants performed an arrow-based version of the Eriksen flanker task, while ERPs (N1, N2, P3), reaction times, accuracy, subjective stress, and electrocardiogram signal were measured. Results showed elevated self-report stress, negative affect, state anxiety, heart rate, and reduced high-frequency heart rate variability in the stress block than in the control block, indicating that the flanker task was performed in a stressful situation. In the flanker task, faster response and larger flanker effect of accuracy were observed for the stress block relative to the control block, indicating increased arousal level and improved conflict detection under stress. Event-related potentials locked to target stimuli in the flanker task revealed that (a) frontal N1 was amplified in the stress block than in the control block, indicating elevated vigilance level under stress; (b) frontal N2 was increased in the stress block than in the control block for both congruent and incongruent trials, indicating more intensive attention control under stress; and (c) Increased P3 in the stress block than in the control block may reflect more allocation of neural resources as a consequence of improved attentional control under stress. These findings suggest that acute psychological stress increases general alertness and promotes attentional control in selective attention processes.

The Change Processes in Selective Attention during Adulthood. Inhibition or Processing Speed?

Selective attention is involved in multiple daily activities. Several authors state that it experiences a decline after 20 years, although there is no agreement regarding the cognitive processes that explain it. Two theories dominate the discussion: The theory of inhibitory inefficiency and the theory of processing speed. At the same time, it has been suggested that there could be complementary relations between both; however, it is not clear what the contribution of inhibition and processing speed is on the changes of selective attention. Therefore, the present study proposes to analyze this contribution, in adults between 20 and 80 years old. To assess selective attention and inhibitory control, two indices of a visual search task were obtained in which participants must identify a target stimulus among a set of distracting stimuli. To evaluate the processing speed, a response speed task was used. The main results indicate that, from the age of 60, a gradual decrease in selective attention begins and that this decline can be largely explained by a decrease in processing speed and inhibitory control. We discuss about the literature on the development of selective attention, the contribution of processing speed, and the inhibitory inefficiency hypothesis.

Interactive effects of HIV and ageing on neural oscillations: independence from neuropsychological performance.

HIV infection is associated with increased age-related co-morbidities including cognitive deficits, leading to hypotheses of HIV-related premature or accelerated ageing. Impairments in selective attention and the underlying neural dynamics have been linked to HIV-associated neurocognitive disorder; however, the effect of ageing in this context is not yet understood. Thus, the current study aimed to identify the interactive effects of ageing and HIV on selective attention processing. A total of 165 participants (92 controls, 73 participants with HIV) performed a visual selective attention task while undergoing magnetoencephalography and were compared cross-sectionally. Spectrally specific oscillatory neural responses during task performance were imaged and linked with selective attention function. Reaction time on the task and regional neural activity were analysed with analysis of covariance (ANCOVA) models aimed at examining the age-by-HIV interaction term. Finally, these metrics were evaluated with respect to clinical measures such as global neuropsychological performance, duration of HIV infection and medication regimen. Reaction time analyses showed a significant HIV-by-age interaction, such that in controls older age was associated with greater susceptibility to attentional interference, while in participants with HIV, such susceptibility was uniformly high regardless of age. In regard to neural activity, theta-specific age-by-HIV interaction effects were found in the prefrontal and posterior parietal cortices. In participants with HIV, neuropsychological performance was associated with susceptibility to attentional interference, while time since HIV diagnosis was associated with parietal activity above and beyond global neuropsychological performance. Finally, current efavirenz therapy was also related to increased parietal interference activity. In conclusion, susceptibility to attentional interference in younger participants with HIV approximated that of older controls, suggesting evidence of HIV-related premature ageing. Neural activity serving attention processing indicated compensatory recruitment of posterior parietal cortex as participants with HIV infection age, which was related to the duration of HIV infection and was independent of neuropsychological performance, suggesting an altered trajectory of neural function.